1. Field of Invention
The present invention concerns a pair of clip-on spectacles for fastening on another pair of spectacles, where the clip-on spectacles include a pair of glasses which are interconnected by a bridge.
2. Description of Related Art
Typical clip-on sunglasses are designed with a bridge between two spectacle glasses, where the bridge keeps the glasses of the spectacles at a predetermined distance which is adapted to the spectacles for which the clip-on spectacles are intended. Alternatively, the optician adapts the clip-on spectacles to the individual spectacles in the shop when the customer buys them. In order to keep the glasses of the clip-on spectacles at their correct mutual distance, the bridge also has the task of stabilising the glasses, why the bridge is made of a rigid material. The clip-on spectacles are secured on the spectacles by means of hooks which often scratch the glasses.
However, in order not to be visible in a dominant way, it is sometimes preferred to design the bridge of a thin rigid metal wire. During storage is it a risk that this metal wire is bent or breaks at the point of soldering, which is a great drawback. Also, there is the problem that they are very dominating with regard to appearance when they are put on spectacles, i.e. they are very visible, contrary to the wish that they be largely invisible. Besides, the clip-on glasses are flat, though having the same area as the spectacles, also during storage.
From French Patent FR 2 875 914, a pair of clip-on spectacles is known, with a U-shaped bridge consisting of a mechanical complicated construction. This solution can be compared to the mechanisms known from the connection of a frame and an arm of a pair of spectacles. Such a solution has the one very large drawback that it is a complicated and expensive solution, with a high degree of vulnerability.